(let ((tl (make-vect 0 1)) 
      (tr (make-vect 1 1)) 
      (bl (make-vect 0 0)) 
      (br (make-vect 1 0))) 
  (segments->painter (list 
                       (make-segment bl tl) 
                       (make-segment tl tr) 
                       (make-segment tr br) 
                       (make-segment br br))) 
  (segments->painter (list 
                       (make-segment bl tr) 
                       (make-segment br tl)))) 

(let ((l (make-vect 0 0.5)) 
      (t (make-vect 0.5 1)) 
      (r (make-vect 1 0.5)) 
      (b (make-vect 0.5 0))) 
  (segments->painter (list 
                       (make-segment l t) 
                       (make-segment t r) 
                       (make-segment r b) 
                       (make-segment b l)))) 
